Laser beam measurement of abdominal sagittal diameter in obese children: a validation study

OBJECTIVES

Sagittal diameter (SAD) has been reported to correlate to visceral fat and cardiovascular risk factors. SAD is measured with the individual lying down, halfway between the lower rib margin and the iliac crest; it represents the mid-height of the abdomen. The aim of this study was to validate SAD measured using a recently-developed laser beam device (SAD(LDB) ) against SAD measured using MRI (SAD(MRI)).

METHODS

Of 48 obese children (25 boys, 23 girls) aged 9-11 years on the waiting list for obesity treatment, 34 agreed to a baseline measurement, which was followed by repeated measurements 6 and 12 months later in 31 and 22 children respectively. MRI was used to examine SAD(MRI) at 5 cm above (SAD(MRI,cra) ) and below (SAD(MRI,cau)) the mid plane of the L4-5 intervertebral disc.

RESULTS

Each of the differences SAD(LBD) - SAD(MRI, cau) and SAD(LBD) - SAD(MRI,cra) was subjected to a repeated-measurements ANOVA; the visit did not have a statistically significant effect in either case (p = 0.19 and p = 0.72, respectively). The difference SAD(LBD) - SAD(MRI, cau) was 1.50 on average (p < 0.0001; CI 1.26-1.74) while the corresponding figure for SAD(LBD) -SAD(MRI, cra) was 1.26 (p < 0.0001; CI 1.04-1.49). Regression of the difference on the mean gave slopes of -0.09 (p = 0.25) and -0.04 (p = 0.57) respectively. Prediction of SAD(MRI) from SAD(LDB) can be performed in different ways: by means of linear regression or by means of an additive correction.

CONCLUSIONS

Thus, this laser device can be used instead of MRI to estimate SAD by using a simple correction.

Both high and low blood pressures risk indicators of death in middle-aged males. Isotonic regression of blood pressure on age applied to data from a 13-year prospective study

This study was performed to investigate whether a moderately sized population of men (n = 954) living in a geographically defined area could be utilized and give valid results in a 13-year prospective study regarding mortality as a function of blood pressure. Isotonic regression of blood pressure on age was used to define groups of men with low, medium, and high blood pressure. Men aged 40-69 years in both extreme groups showed an excess death risk in comparison with those in the medium group. Thus, mortality appeared to be a U-shaped function of blood pressure in this age group. The mortality ratios of the low and high blood pressure groups vis-à-vis the medium group were higher during the first than during the second half of the observation period. Chronic diseases at the time of the initial examination were more common among men who died in the lowest blood pressure group than among those who died in the medium group. In males aged 70-99 years, blood pressure appeared to be of less importance as a risk indicator of death.

Relationship between fibrinolytic activity and gingival inflammatory reaction in young individuals

The fibrinolytic system (the plasminogen activating system) is involved in several physiological and pathological processes. Through the transformation of plasminogen to the aggressive broad spectrum protease plasmin, potent enzymatic activity is released. Plasmin acts directly on connective tissue components, and indirectly by activating proforms of the metalloproteinases. The destructive potential of the fibrinolytic system may thus be of importance for the initiation and progression of periodontal diseases. Earlier studies have shown high concentrations of the plasminogen activator t-PA and its inhibitor PAI-2 in gingival crevicular fluid (GCF) as well as enhanced concentrations in areas of gingival inflammation. The aim of this study was to investigate a possible relationship between the gingival inflammatory reactivity and the fibrinolytic activity in gingival crevicular fluid. Thirty-one young individuals took part in the study. Gingival Index scores and Plaque Index scores were assessed and used to formulate a score expressing an individuals' inflammatory response to microbial plaque levels (Relative G/P score). The fibrinolytic activity of GCF was assessed with a fibrin gel lysis assay, and the levels of t-PA and PAI-2 were assayed with ELISAs. All samples showed fibrinolytic activity. A positive correlation between the fibrinolytic activity and Relative G/P score was found. Thus, in individuals with an enhanced reactivity to dental plaque, a higher plasminogen activating activity in GCF was seen. This indicates a higher potential for tissue proteolysis in these individuals, possibly facilitating spread and deeper involvement of the lesions.

Accuracy of a first diagnosis of asthma in primary health care

BACKGROUND

In a postal questionnaire study, the prevalence of asthma in southern Sweden has been found to be 5.5%. However, the register prevalence of asthma obtained from the medical records in the same municipality and age groups was found to be only 2.1%.

OBJECTIVES

The aims of the study were to investigate whether the low register prevalence of asthma was caused by an underdiagnosis of asthma in primary health care and to validate a first diagnosis of asthma set by GPs in primary health care.

METHODS

During a period of 3 months in 1997, all patients seeking care in the primary health care units of the municipality of Lund (population 171 877) with upper or lower airway infections, prolonged cough, allergic rhinitis, fatigue or a first positive diagnosis of asthma were recorded ( n = 3025).

RESULTS

In the whole group of 3025 patients, 99 patients were found to have received a diagnosis of asthma for the first time during the study period. The diagnosis was verified in 52 of those 68 patients who attended a follow-up and examination by a respiratory physician. Among the remaining 2926 patients, 221 patients were selected randomly to constitute a control group. In this group, three patients were found to have asthma. Thus, the specificity of an asthma diagnosis set in primary health care was 0.99 [95% confidence interval (CI) 0.99-1.00] and the sensitivity was 0.59 (95% CI 0.31-0.81).

CONCLUSIONS

The GPs in this study were good at excluding those who did not have asthma (specificity 99%) but less good in correctly diagnosing those who actually had current asthma (sensitivity 59%), which suggests an underdiagnosis of asthma.

Carotid artery stenosis: contrast-enhanced MR angiography with two different scan times compared with digital subtraction angiography

Contrast enhanced magnetic resonance angiography (CE MRA) is a non-invasive alternative to conventional digital subtraction angiography (DSA). CE MRA is increasingly used as a complement to Duplex in the preoperative assessment of carotid artery stenosis. The purpose of this study was to determine if CE MRA could replace preoperative DSA. CE MRA with a scan time of 10 or 28 s was performed in 24 consecutive patients who were scheduled for preoperative DSA because of Duplex-verified severe carotid artery stenosis. Two neuroradiologists measured the degree of stenosis with three different methods, and the image quality was evaluated. DSA was used as the gold standard. For detection of severe stenosis (N. American symptomatic carotid endarterectomy trial (NASCET) > or =70%; European symptomatic carotid endarterectomy trial (ECST) > or =80%; common carotid artery method (CCAM) > or =80%), the sensitivity of CE MRA maximum intensity projection (MIP) compared with DSA was 82%-100 %, the specificity was 74%-93% and the accuracy was 77%-90%. The inter-observer agreement was higher, the image quality was better and the intracranial main arteries were better visualized with the 28 s than with the 10 s scan time. The enhancement of the jugular veins seen in 17% of the 10 s scans and in 58% of the patients with the 28 s scans did not interfere with the evaluation of the carotid arteries. CE MRA, preferably with a scan time of 28 s, can replace DSA in the preoperative assessment of most patients with carotid artery stenosis.

Reduced cardiovascular morbidity and mortality in hypertensive diabetic patients on first-line therapy with an ACE inhibitor compared with a diuretic/beta-blocker-based treatment regimen: a subanalysis of the Captopril Prevention Project

OBJECTIVE

The Captopril Prevention Project (CAPPP) evaluated the effects of an ACE inhibitor-based therapeutic regimen on cardiovascular mortality and morbidity in hypertension. One planned subanalysis of the CAPPP was to evaluate the outcome in the diabetic patient group.

RESEARCH DESIGN AND METHODS

In the CAPPP, 572 (4.9% of 10,985 hypertensive patients) had diabetes at baseline and were studied according to a prospective, randomized, open, blinded, end point trial design. Patients aged 25-66 years with diastolic blood pressure > or =100 mmHg were included and randomized to receive either captopril or conventional antihypertensive treatment (diuretics and/or beta-blockers).

RESULTS

The primary end point, fatal and nonfatal myocardial infarction and stroke as well as other cardiovascular deaths, was markedly lower in the captopril than in the conventional therapy group (relative risk [RR] = 0.59; P = 0.018). Specifically, cardiovascular mortality, defined as fatal stroke and myocardial infarction, sudden death, and other cardiovascular death, tended to be lower in the captopril group (RR = 0.48; P = 0.084), and no difference was observed between the study groups for stroke (RR = 1.02; P = 0.96). Myocardial infarctions were less frequent in the captopril group than in the conventional therapy group (RR = 0.34; P = 0.002). Furthermore, total mortality was lower in the captopril as compared with the conventional therapy group (RR = 0.54; P = 0.034). Patients with impaired metabolic control seemed to benefit the most from ACE inhibitor-based therapy.

CONCLUSIONS

Captopril is superior to a diuretic/beta-blocker antihypertensive treatment regimen in preventing cardiovascular events in hypertensive diabetic patients, especially in those with metabolic decompensation.

Relation between drug treatment and cancer in hypertensives in the Swedish Trial in Old Patients with Hypertension 2: a 5-year, prospective, randomised, controlled trial

BACKGROUND

Is cancer related to hypertension and blood pressure? Do antihypertensive drugs promote cancer? Do antihypertensive drugs protect against cancer? We previously analysed the frequency of cardiovascular mortality and morbidity in elderly people who participated in the Swedish Trial in Old Patients with Hypertension 2 (STOP-Hypertension-2). We have also looked at the frequency of cancer in these patients.

METHODS

We randomly assigned 6614 elderly patients with hypertension (mean age 76 years, median time of follow-up 5.3 years) to one of three treatment strategies: conventional drugs (diuretics or b-blockers), calcium antagonists, or ACE inhibitors. We matched the patients to the Swedish Cancer Registry and compared our findings with expected values based on age, sex, and calendar-year-specific reference frequencies for the general Swedish population. We also compared the number of cancers between the three treatment groups.

FINDINGS

At baseline, 607 (9%) patients had previous malignant disease. Diagnoses were closely similar to the distribution of cancer types that might be seen in elderly patients. During follow-up, there were 625 new cases of cancer in 590 patients. The frequency of cancer did not differ significantly between the treatment strategies, including all cancers and those at individual sites. The standardised incidence ratios (SIRs) for all cancers were also close to unity: 0.92 (95% CI 0.80-1.06) for conventional drugs, 0.96 (0.83-1.10) for calcium antagonists, and 0.99 (0.86-1.13) for ACE inhibitors.

INTERPRETATIONS

No difference in cancer risk was seen between patients randomly assigned to conventional drugs, calcium antagonists, or ACE inhibitors. Thus, the general message to the practising physician is that more attention should be given to getting the blood pressure down than to the risk of cancer.

Familial related risk-factors in the development of chronic bronchitis/emphysema as compared to asthma assessed in a postal survey

There is a lack of knowledge to which extent heredity or familial risk factors are involved in the development of chronic bronchitis/emphysema (CBE). Smoking is regarded as the most important risk factor, but only about 15% of smokers develop airway obstruction. We evaluated the importance of familial risk factors compared to smoking and ex-smoking using an epidemiological approach. In 1992, a postal questionnaire was distributed to a study sample. In all, 43 questions were asked, in a previously evaluated questionnaire, regarding respiratory symptoms, self-reported lung diseases, smoking habits and familial occurrence of chronic bronchitis and asthma. The questionnaire was sent to 12,073 adults living in the southernmost part of Sweden. The age range was 20-59 years with an equal gender distribution. The study sample was drawn from the population records. The questionnaire was answered by 8469 subjects (70.1%), of whom 392 subjects (4.6%) stated that they had or had had CBE and 469 subjects (5.5%) stated that they had or had had asthma. In a model with logistic regression using the five explanatory variables gender, age, familial occurrence for asthma, familial occurrence for CBE and current or ex-smoking the most important risk factors for CBE were familial occurrence for chronic bronchitis [Odds ratios (OR): 5.19, 95% confidence interval (CI): 4.09-6.60, p = 0.000] and current or ex-smoking (OR: 1.74, 95% CI: 1.41-2.14, p = 0.000). The most important risk factors for asthma were familial occurrence for asthma (OR: 3.71, 95% CI: 3.06-4.51, p = 0.000) and current or ex-smoking (OR: 1.33, 95% CI: 1.09-1.61, p = 0.004). We have found that familial occurrence for CBE in first degree relatives together with smoking is a stronger risk factor for the development of CBE than is smoking.

A historical cohort study of kidney damage in long-term lithium patients: continued surveillance needed

BACKGROUND

Insufficient knowledge on the longitudinal fate of renal function in lithium patients incited this retrospective study of 149 patients.

METHOD

Medical record review of a lithium cohort (N = 149), 8--12 years after an initial renal function study.

RESULTS

Twenty-one patients had died, one from uremia probably not caused by lithium, and 42 had discontinued lithium. Reduced urinary concentrating capacity (Umax) or glomerular filtration rate (GFR) was not more frequent among deceased or off-lithium patients than among the 86 patients who were on lithium at follow-up. In 63 of the latter patients, Umax had been re-examined after the initial study, and GFR in 29 patients. Reduced Umax and GFR had become twice as common, and average Umax and GFR had decreased significantly. The reduction of GFR was associated with lithium treatment duration and age, and reduced Umax with treatment duration only.

CONCLUSIONS

Reduced renal function is not a major cause of treatment discontinuation but becomes increasingly common with treatment duration.Limitations. Missing data rendered the interpretation difficult in some respects. Clinical relevance. The increased proportion of patients with reduced GFR and Umax with time implies an increased risk of potentially lethal dehydration and lithium intoxication. Continued surveillance of urinary output and GFR is therefore necessary.

Comparison of antihypertensive treatments in preventing cardiovascular events in elderly diabetic patients: results from the Swedish Trial in Old Patients with Hypertension-2. STOP Hypertension-2 Study Group

BACKGROUND

The benefits of treating hypertension in elderly diabetic patients, in terms of achieving reductions in cardiovascular morbidity and mortality, have been documented in several recent prospective trials. There has, however, been some controversy regarding the effect of different antihypertensive drugs on the frequency of myocardial infarction in this group of patients.

DESIGN

STOP Hypertension-2 was a prospective, randomized, open trial with blinded endpoint evaluation.

METHODS

We studied 6614 elderly patients aged 70-84 years; 719 of them had diabetes mellitus at the start of the study (mean age 75.8 years). Patients were randomly assigned to one of three treatment strategies: conventional antihypertensive drugs (diuretics or beta-blockers), calcium antagonists, or angiotensin converting enzyme (ACE) inhibitors.

RESULTS

Reduction in blood pressure was similar in the three treatment groups of diabetics. The prevention of cardiovascular mortality was also similar; the frequency of this primary endpoint did not differ significantly between the three groups. There were, however, significantly fewer (P = 0.025) myocardial infarctions during ACE inhibitor treatment (n = 17) than during calcium antagonist treatment (n = 32; relative risk 0.51, 95% confidence interval 0.28-0.92); but a (non-significant) tendency to more strokes during ACE inhibitor treatment (n = 34 compared with n = 29; relative risk 1.16, 95% confidence interval 0.71-1.91).

CONCLUSION

Treatment of hypertensive diabetic patients with conventional antihypertensive drugs (diuretics, beta-blockers, or both) seemed to be as effective as treatment with newer drugs such as calcium antagonists or ACE inhibitors.

Randomised trial of effects of calcium antagonists compared with diuretics and beta-blockers on cardiovascular morbidity and mortality in hypertension: the Nordic Diltiazem (NORDIL) study

BACKGROUND

Calcium antagonists are a first-line treatment for hypertension. The effectiveness of diltiazem, a non-dihydropyridine calcium antagonist, in reducing cardiovascular morbidity or mortality is unclear. We compared the effects of diltiazem with that of diuretics, beta-blockers, or both on cardiovascular morbidity and mortality in hypertensive patients.

METHODS

In a prospective, randomised, open, blinded endpoint study, we enrolled 10,881 patients, aged 50-74 years, at health centres in Norway and Sweden, who had diastolic blood pressure of 100 mm Hg or more. We randomly assigned patients diltiazem, or diuretics, beta-blockers, or both. The combined primary endpoint was fatal and non-fatal stroke, myocardial infarction, and other cardiovascular death. Analysis was done by intention to treat.

FINDINGS

Systolic and diastolic blood pressure were lowered effectively in the diltiazem and diuretic and beta-blocker groups (reduction 20.3/18.7 vs 23.3/18.7 mm Hg; difference in systolic reduction p<0.001). A primary endpoint occurred in 403 patients in the diltiazem group and in 400 in the diuretic and beta-blocker group (16.6 vs 16.2 events per 1000 patient-years; relative risk 1.00 [95% CI 0.87-1.15], p=0.97). Fatal and non-fatal stroke occurred in 159 patients in the diltiazem group and in 196 in the diuretic and beta-blocker group (6.4 vs 7.9 events per 1000 patient-years; 0.80 [0.65-0.99], p=0.04) and fatal and non-fatal myocardial infarction in 183 and 157 patients (7.4 vs 6.3 events per 1000 patient-years; 1.16 [0.94-1.44], p=0.17).

INTERPRETATION

Diltiazem was as effective as treatment based on diuretics, beta-blockers, or both in preventing the combined primary endpoint of all stroke, myocardial infarction, and other cardiovascular death.

Randomised trial of old and new antihypertensive drugs in elderly patients: cardiovascular mortality and morbidity the Swedish Trial in Old Patients with Hypertension-2 study

BACKGROUND

The efficacy of new antihypertensive drugs has been questioned. We compared the effects of conventional and newer antihypertensive drugs on cardiovascular mortality and morbidity in elderly patients.

METHODS

We did a prospective, randomised trial in 6614 patients aged 70-84 years with hypertension (blood pressure > or = 180 mm Hg systolic, > or = 105 mm Hg diastolic, or both). Patients were randomly assigned conventional antihypertensive drugs (atenolol 50 mg, metoprolol 100 mg, pindolol 5 mg, or hydrochlorothiazide 25 mg plus amiloride 2.5 mg daily) or newer drugs (enalapril 10 mg or lisinopril 10 mg, or felodipine 2.5 mg or isradipine 2-5 mg daily). We assessed fatal stroke, fatal myocardial infarction, and other fatal cardiovascular disease. Analysis was by intention to treat.

FINDINGS

Blood pressure was decreased similarly in all treatment groups. The primary combined endpoint of fatal stroke, fatal myocardial infarction, and other fatal cardiovascular disease occurred in 221 of 2213 patients in the conventional drugs group (19.8 events per 1000 patient-years) and in 438 of 4401 in the newer drugs group (19.8 per 1000; relative risk 0.99 [95% CI 0.84-1.16], p=0.89). The combined endpoint of fatal and non-fatal stroke, fatal and non-fatal myocardial infarction, and other cardiovascular mortality occurred in 460 patients taking conventional drugs and in 887 taking newer drugs (0.96 [0.86-1.08], p=0.49).

INTERPRETATION

Old and new antihypertensive drugs were similar in prevention of cardiovascular mortality or major events. Decrease in blood pressure was of major importance for the prevention of cardiovascular events.

Effect of angiotensin-converting-enzyme inhibition compared with conventional therapy on cardiovascular morbidity and mortality in hypertension: the Captopril Prevention Project (CAPPP) randomised trial

BACKGROUND

Angiotensin-converting-enzyme (ACE) inhibitors have been used for more than a decade to treat high blood pressure, despite the lack of data from randomised intervention trials to show that such treatment affects cardiovascular morbidity and mortality. The Captopril Prevention Project (CAPPP) is a randomised intervention trial to compare the effects of ACE inhibition and conventional therapy on cardiovascular morbidity and mortality in patients with hypertension.

METHODS

CAPPP was a prospective, randomised, open trial with blinded endpoint evaluation. 10,985 patients were enrolled at 536 health centres in Sweden and Finland. Patients aged 25-66 years with a measured diastolic blood pressure of 100 mm Hg or more on two occasions were randomly assigned captopril or conventional antihypertensive treatment (diuretics, beta-blockers). Analysis was by intention-to-treat. The primary endpoint was a composite of fatal and non-fatal myocardial infarction, stroke, and other cardiovascular deaths.

FINDINGS

Of 5492 patients assigned captopril and 5493 assigned conventional therapy, 14 and 13, respectively, were lost to follow-up. Primary endpoint events occurred in 363 patients in the captopril group (11.1 per 1000 patient-years) and 335 in the conventional-treatment group (10.2 per 1000 patient-years; relative risk 1.05 [95% CI 0.90-1.22], p=0-52). Cardiovascular mortality was lower with captopril than with conventional treatment (76 vs 95 events; relative risk 0.77 [0.57-1-04], p=0.092), the rate of fatal and non-fatal myocardial infarction was similar (162 vs 161), but fatal and non-fatal stroke was more common with captopril (189 vs 148; 1.25 [1-01-1-55]. p=0.044).

INTERPRETATION

Captopril and conventional treatment did not differ in efficacy in preventing cardiovascular morbidity and mortality. The difference in stroke risk is probably due to the lower levels of blood pressure obtained initially in previously treated patients randomised to conventional therapy.

Improved classifications of myocardial bull's-eye scintigrams with computer-based decision support system

In a recent study, artificial neural networks were trained to detect coronary artery disease using scintigraphic data as input. The performance of the networks was better than that of human experts using coronary angiography as a gold standard. In clinical practice, this type of neural networks will not take over the decision-making process from the physician but will assist by proposing an interpretation of the scintigram. The purpose of this study was to assess the influence of such decision support on the interpretations of the physicians.

METHODS

A population of 135 patients who had undergone both myocardial 99mTc-sestamibi rest/stress scintigraphy and coronary angiography within a 3-mo period was studied. An image set consisting of the bull's-eye rest, stress, difference and quote images was constructed for each patient. Three experienced physicians independently classified all image sets regarding the presence and/or absence of coronary artery disease in two vascular territories using a four-grade scale. The physicians classified the image sets twice with and twice without the advice of artificial neural networks.

RESULTS

The joint evaluation of the three physicians showed significantly improved performance with decision support, measured as increases in the areas under the receiver operating characteristic curves from 0.65 to 0.70 (P = 0.018) and from 0.79 to 0.82 (P = 0.006) for two vascular territories. Furthermore, the joint evaluation showed significantly less intraobserver and interobserver variability with decision support.

CONCLUSION

Physicians classifying myocardial bull's-eye images benefit from the advice of artificial neural networks. These results show the high potential for neural networks as clinical decision support systems.

Old patients with hypertension. A 25-year observational study of a geographically defined population (Dalby), aged 67 years at entry

OBJECTIVES

To evaluate the impact of hypertension and other risk factors on mortality, in particular cardiovascular mortality, in a geographically defined population of elderly subjects.

DESIGN

An observational 25-year study of a total population.

SETTING

The local health centre in the village of Dalby in southern Sweden.

SUBJECTS

All men and women born in 1902 or 1903, living in Dalby, were, at the age of 67, invited for medical and psychological examinations. The population comprised 188 subjects (109 men and 79 women); 156 (83%) of them took part in the first medical examination. Blood pressure, heart rate, weight and height were measured and laboratory tests performed at entry. Blood pressures were thereafter recorded six times, and this report is based on a 25-year follow-up period ending in October 1994.

MAIN OUTCOME MEASURES

Survival analyses were performed, based on definition of underlying causes of death, divided into all-cause and cardiovascular.

RESULTS

At entry, females had higher blood pressure than males, both at baseline and during the first 16 years of the study, regardless of whether they were hypertensives or not. Most men smoked but only a few women. At the end of the follow-up of the present study in 1994, 138 out of 156 (88%) subjects had died and only 18 (12%) remained alive; 78 (57%) had died of a cardiovascular disease. In men, a diagnosis of hypertension as well as increased blood pressure at entry was associated with increased mortality. In women this was the case for blood pressure and risk of cardiovascular mortality. In men, both systolic and diastolic blood pressures during the study were significant risk factors for death, whereas in women this was not the case.

CONCLUSIONS

Elderly male hypertensives ran an increased mortality risk even though they were treated according to the then current guidelines; female hypertensives seemed to run the same risk of dying as normotensive females.

The effect of genetic factors for longevity: a comparison of identical and fraternal twins in the Swedish Twin Registry

BACKGROUND

The relative importance of genetic influences on longevity was studied on data from the population-based Swedish Twin Registry.

METHODS

A sample of 3,656 identical and 6,849 like-sexed fraternal twin pairs was studied regarding mortality rates and within-pair similarity for age at death. Genetic and environmental contributions to variation in longevity, expressed by integrated mortality rates, were estimated from a subsample of 1,734 twin pairs reared together and 130 twin pairs reared apart from the cohorts born 1886 to 1900.

RESULTS

The intraclass correlation coefficients suggested that the genetic effect was small, and, for males, perhaps absent. Among pairs in which both twins died relatively young and among pairs in which both twins lived until very old age, the variance in age at death seemed to have no genetic component. Model fitting procedures based on twins reared apart and twins reared together indicated that most of the variance in longevity was explained by environmental factors.

CONCLUSIONS

Over the total age range examined, a maximum of around one third of the variance in longevity is attributable to genetic factors, and almost all of the remaining variance is due to nonshared, individual specific environmental factors. The evidence that genetic factors play a minor role depending upon age at death merits further examination.

The Captopril Prevention Project (CAPPP) in hypertension--baseline data and current status

The Captopril Prevention Project (CAPPP) is an ongoing intervention study conducted in 11,019 hypertensive patients in Sweden and Finland. Patients have been randomized to receive either conventional antihypertensive therapy (diuretics and/or beta-blockers) or captopril-based treatment. A prospective, randomized, open, blinded-endpoint evaluation (PROBE) study design is used to compare these two therapeutic regimens as regards cardiovascular morbidity and mortality. The rationale for the CAPPP Study are the many observations of beneficial effects of ACE inhibition, as compared to diuretics and beta-blockers, on intermediary endpoints such as insulin sensitivity, serum lipoproteins, left ventricular hypertrophy and renal function. Captopril has also been shown to be markedly effective in the treatment of left ventricular dysfunction as well as congestive heart failure. The hypothesis is that these differences might result in improved risk reduction when ACE inhibitors are used in the treatment of hypertension. The present paper describes the baseline data and the changes in blood pressure during the first year in the total cohort. During the first year the average blood pressure was reduced by 11/8 mm Hg. A number of substudies have been conducted in the CAPPP Study. In one of these insulin sensitivity was compared in a subgroup of the patients using the euglycemic insulin clamp technique. In another substudy the ACE gene was sequenced and some new polymorphisms were discovered. Several other substudies are in progress or in the planning phase. The main results of the CAPPP Study should be available by mid-1998. Some of the intended anayses of the final results as well as other planned substudies are briefly described here.

Reference intervals for the glomerular filtration rate and cell-proliferation markers: serum cystatin C and serum beta 2-microglobulin/cystatin C-ratio

Recent studies have indicated that serum and plasma cystatin C are better markers for glomerular filtration rate (GFR) than serum creatinine, ubiquitously used for this purpose. To fully exploit the value of serum and plasma cystatin C as GFR markers, reliable age and sex-correlated reference intervals are required. The present study comprised cystatin C determinations in plasma and sera from 259 individuals from a well-defined area in the southernmost part of Sweden. From demographic lists two men and two women were randomly selected from each one-year birth cohort above 20 years of age. No sex differences were found for plasma and serum cystatin C, whereas an increase in the cystatin C levels with age was noted, corresponding to the known age-related decrease in GFR. The following reference intervals are recommended for practical clinical use: S-Cystatin C (both sexes): 20-50 years, 0.70-1.21 mg l-1 and 50+ years, 0.84-1.55 mg l-1. The same samples were also used for determination of beta 2-microglobulin levels in order to calculate reference intervals for the beta 2-microglobulin/cystatin C-ratio, which is a more distinct marker for cell proliferation, particularly lymphoproliferation, than is the serum level of beta 2-microglobulin alone, since the ratio should be virtually uninfluenced by GFR. The beta 2-microglobulin/cystatin C-ratios were uninfluenced by sex and age and 1.45-2.43 is recommended as the serum reference interval for practical clinical use. Serum creatinine was determined in the same samples and the creatinine level was found to be strongly influenced by sex and weakly by age.

Decrease in high density lipoprotein cholesterol during prolonged storage. CELL Study Group

Different studies on the stability of high density lipoprotein cholesterol (HDL) in frozen serum or plasma have yielded conflicting results, namely increase, decrease, or no change at all during prolonged storage under freezing conditions. As part of a major trial on lipid-lowering strategies we statistically demonstrated a time-related decrease in HDL cholesterol during storage up to 46 months at -20 degrees C. We therefore re-analysed 85 frozen samples that had been analysed fresh and then stored from 26 to 46 months, using the dextran sulphate 500/Mg2+ method. A linear regression analysis of change in HDL cholesterol on time was performed. The slope was significantly negative (p < 0.0005). The regression equation was (decrease in HDL) = 0.05 - 0.008 x (time in months), i.e. after 6 months' storage at -20 degrees C there was almost a 1% decrease in the HDL cholesterol concentration per month of storage.

Infantile colic--less common than previously estimated?

A two-part population-based study investigating the occurrence of infantile colic was undertaken, in which 92% of mothers with newborn healthy infants were reached. In the prospective part 152 mothers ("diary group") registered crying and fussing in their infants during 12 weeks. In the retrospective part 224 mothers ("interview group") were contacted by telephone at an infant age of 5-7 months. The colic occurrence was determined according to four different definitions; the rate varied from 3.3 to 17.1%. The classical "Wessel-type" colic was present in 9.3%. Colic defined as "crying seen as a problem by parent" was present in 12.1% of the "interview group", but in only 3.3% of the "diary group". Some earlier studies may have overestimated colic occurrence. Another possibility is an actual decline. The contributive part of preventive measures is discussed.

Influence of social factors on sugary products behavior in 4-year-old children with regard to dental caries experience and information at child health centers

The aim was to analyze the steering effects of 15 social factors on sugary products behavior at 4 years of age in 177 children. The parents had in most cases received information on dental health care at child health centers, with due respect to the level of caries among the children, who were classified as 'healthy' (no caries experience) (n = 83) or 'diseased' (caries experience) (n = 84). The parents filled in a mailed diet history form. Only sugary products unsuitable from a cariologic point of view were considered. The products were given scores reflecting the frequency of intake. The social factors were social background, family, information, and conceptual factors. By means of multiple regression analysis, explanatory values of the social variables for sugary products behavior were estimated. For the total material, 13% of the variance was explained by all variables combined. Among the social background factors, 'parents' age' was statistically significant (p < 0.05). Among family factors, 'day-care mainly at home' and 'oldest child' were the most important. All information factors proved to be nonsignificant. Of the conceptual factors, only 'importance of genetic factors' was statistically significant. For the healthy group 26% of the variance was explained by all variables. 'Mother's age', 'importance of genetic factors', and 'oldest child' were statistically significant. For the diseased group all variables were nonsignificant. Explanatory values were negligible. The important conclusions were that very few traditionally conceived social variables seem to influence 4-year-old children's sugar behavior. Parents of children with caries appear to be a heterogeneous group with an irrational behavior.

Reference intervals and decision limits for plasma lipids and lipoproteins: a practical evaluation of current recommendations

As part of a longitudinal study--the Kristianstad Survey--we measured plasma cholesterol, HDL- and LDL-cholesterol, triglycerides and lipoprotein (a) in a reference group consisting of 203 men and women aged 20-80, randomly sampled from a well-defined area in the southernmost part of Sweden. The selection of reference individuals and the collection of specimens for assay of the constituents were performed in accordance with current recommendations. The results were subjected to statistical analyses both with and without application of exclusion criteria. Application of the theoretical exclusion criteria resulted in the exclusion of 22% of the participants; however, this procedure had a remarkably weak impact on the results: the mean values and the standard deviations were almost unaltered. The mean (standard deviation) for cholesterol was 5.9 (1.3) mmol l-1, for HDL-C 1.1 (0.3) mmol l-1, and for LDL-C 4.3 (1.2) mmol l-1. Women had higher values than men. Plasma triglycerides were positively skewed; their median and Q3-Q1-values were 1.0 and 0.5 mmol l-1 respectively, men higher than women. There was an increase with age for cholesterol and LDL-C in both sexes and for triglycerides in women. The steepest increase of cholesterol values with age in women coincided with menopause, which have a more clear-cut separation between high and low cholesterol values than did any age limit.

Cold climate is an important factor in explaining regional differences in coronary mortality even if serum cholesterol and other established risk factors are taken into account

Earlier studies have shown a strong regional association between cold climate and coronary mortality in Sweden and that coronary mortality is more strongly associated with cold climate than with other explanatory factors such as drinking water hardness, socioeconomic factors, tobacco and sales of butter. To examine the joint impact of these factors and to investigate regional differences in serum cholesterol and their relation to cold climate and coronary mortality, regression analyses were performed with 259 municipalities in Sweden as units. Mortality from acute myocardial infarction in men aged 40-64 during 1975-1984 was used as the dependent variable. A cold index was calculated, this index and the above mentioned factors were used as explanatory variables. The main results were: Cold index was the strongest factor when introduced into a multiple regression model. Four other strong factors had to be used to obtain the same explanatory strength as cold index did alone, and even when introduced as the last factor, cold index increased the coefficient of determination substantially. In a subsample of 37 municipalities, serum cholesterol was not significantly associated with coronary mortality. However, there was a significant correlation between cold index and serum cholesterol.

Calcified cartilage zone and its dimensional relationship to the articular cartilage in the human temporomandibular joint of elderly individuals

The aim was to describe the appearance of the calcified cartilage zone (CCZ) and to determine its dimensional relationship to the articular cartilage thickness in the normal human temporomandibular joint. An autopsy material comprising 21 joints from 12 elderly individuals was examined microscopically. The appearance of the CCZ was examined, and the thickness of the CCZ and of the total articular cartilage was measured in 18 different positions in each joint. The CCZ was outlined by a flat or gently undulating tidemark and an irregular osteochondral junction. The cellularity of the CCZ varied extensively. The cells were numerous in the CCZ when the overlying articular cartilage displayed high cellularity. Statistical analysis of the measurements demonstrated a relationship (p < 0.001) between the thickness of the CCZ and of the articular cartilage. Our findings, both qualitative and quantitative, indicate a close relationship between the physiology of the CCZ and of the overlying articular cartilage.

Spatial memory and stereotypic behaviour of animals in radial arm mazes

The symmetric radial arm maze, described by Olton in 1976, has developed into an important tool for the study of spatial memory. In a typical test an animal is placed in the centre of the maze, which contains some small piece of food at the end of each arm. The sampling behaviour of the animal is then recorded. In such studies the score (number of choices of arms which still contain food) of the animal is normally compared with the score of an imaginary animal which changes arms entirely at random. In a new method of analysis the non-random score of the animal is split into two parts, one depending on memory and one on stereotypic choice behaviour. Even mild departures from randomness are shown to alter considerably the expected 'random' score in an eight-armed maze. The part of the score claimed to depend on memory was shown to increase when the animals learn to search the maze, the stereotypic part did not. The general effect from stereotypic choice behaviour is shown to result, in most animals, in an increase in the total score. In an eight-armed maze this increase may amount to more than 20% of the total non-random score, even in a well-trained animal. The effect is less pronounced in mazes with 16 arms. It has been proposed that hippocampal lesions produce a stereotypic behaviour. We propose, based on our analysis, that the stereotypic behaviour is not produced but revealed by hippocampal lesions which destroy almost completely the memory-guided behaviour masking the stereotypic behaviour in the intact animal.

Usefulness of self-measured blood pressure when diagnosing mild hypertension

Blood pressure (BP) measured by the patients themselves at home and at their workplaces (self BP) and office blood pressure (office BP) were compared with ambulatory BP (amb BP) in 41 middle-aged borderline hypertensive men when diagnosing hypertension. Ambulatory BP was used as the 'gold standard'. The mean (standard deviation) value for office BP was 142/89 (14/7), self BP 143/92 (14/8), and amb BP 134/88 (12/6) mmHg. There was no difference between diastolic office BP and self BP as instruments for diagnosing hypertension. Furthermore, combining the two added little to the diagnostic value obtained from only one of them.

Socioeconomic factors in the community fail to explain the high coronary mortality in cold parts of Sweden

A regional association between cold climate and coronary mortality in Sweden has already been described. This study aimed to investigate whether this association can be explained by differences in socioeconomic factors and found that there was a regional association between coronary mortality and the following socioeconomic factors: prevalence of manual workers (D = 0.22), unemployment rates (D = 0.19), and proportion of low income earners (D = 0.17). However, these associations were substantially weaker than that between cold climate and coronary mortality (D = 0.39), and when cold climate was introduced into the statistical model the explanatory power of the socioeconomic factors diminished substantially and only the percentage of manual workers enhanced the explanatory power of cold climate. Regional variation in coronary mortality could not be attributed to long distance to emergency hospital. To conclude, the strong association between cold climate and coronary mortality could not be attributed to the influence of socioeconomic factors.

Water hardness does not contribute substantially to the high coronary mortality in cold regions of Sweden

Earlier studies have shown an association between cold climate and high coronary mortality. The aim of this study was to elucidate in more detail the effect of drinking water hardness on this association. Drinking water parameters were obtained from 259 municipalities in Sweden over a 10-year period. During the same period a 'cold index' was calculated for each municipality. Standardized coronary mortality rates in men aged 40-64 years were used. A negative association was found between water hardness and coronary mortality (coefficient of determination k = 0.080). A much stronger association was found between coronary mortality and cold index (D = 0.389). When coronary mortality was explained by both water hardness and cold index, the association was not significantly strengthened (D = 0.391). Water hardness was negatively correlated with cold index (r = 0.55). We conclude that the association between cold climate and coronary mortality was stronger than that between drinking water hardness and coronary mortality, and that it persisted after stratification for water hardness.

High coronary mortality in cold regions of Sweden

The hypothesis that cold climate is associated with high coronary mortality in Sweden is tested. Cold exposure was calculated in each of the 284 municipalities of Sweden. There was a significant association between cold exposure and coronary mortality in both sexes in all age groups. The strongest association was found in men aged 40-64 years (coefficient of determination k = 0.39). The decile of men aged 40-64 years who lived in the coldest municipalities had a 40% excess mortality. A significant association was also found between cold exposure and mortality from cerebrovascular diseases. We conclude that there is a strong regional association between cold exposure and high coronary mortality.

Smoking habits, sales of fat and antihypertensives fail to explain the high coronary mortality in cold regions of Sweden

A previous study has shown a strong regional association between cold climate and coronary mortality in Sweden. The present study intended to elucidate further this association, in particular whether or not it could be attributed to smoking, hypertension and fat consumption. The 284 Swedish municipalities were used as units. The outcome was mortality (SMR) from acute myocardial infarction in men aged 40-64. Prevalence of smoking and use of snuff was estimated by interviews. Sales of antihypertensive drugs were used to estimate prevalence of hypertension. Sales of butter and estimates of consumption of saturated fat by interviews were used to estimate the consumption of fat. Weighted determination coefficients (D) were calculated. Apart from the strong association between cold climate and coronary mortality (D = 0.39), an association was shown between fat consumption and coronary mortality (D = 0.22). A weaker association was found between prevalency of snuffing and coronary mortality (D = 0.15) and between sales of butter and coronary mortality (D = 0.10) and the weakest between sales of antihypertensives and coronary mortality (D = 0.06). No association was found between prevalence of smoking and coronary mortality. When the other explanatory factors were added to cold climate in the model no substantial enhancement of the association was achieved. Cold exposure was correlated to the other explanatory factors. To conclude, this study showed that the strong association between cold exposure and coronary mortality was not affected by the regional variation in the estimates of fat consumption, hypertension or tobacco use.

A prospective study of first-incidence depression. The Lundby study, 1957-72

The present study is based on the so-called 1957 Lundby cohort, a geographically defined normal Swedish population of 2612 individuals who were evaluated for mental disorders in 1957 and 1972. The annual age-standardised first incidence of depression, with or without other psychiatric symptoms, all degrees of impairment included, was found to be 4.3 per 1000 person years in men and 7.6 per 1000 person years in women. Up until 70 years of age, the cumulative probability of suffering a first episode of depression was 27% in men and 45% in women.

A semiautomatic image analyzer for cell counts in monolayers. I. Construction, experimental procedure, and precision obtained

A simple, flexible, low-cost image analyzer system is presented for determination of the total number of cells and the number of viable cells in monolayers of nonconfluent cells. Viable cells were identified and counted using an immunofluorescence method using fluorescein diacetate. Alveolar macrophages from rabbits were used. The different possible counting procedures that could be performed are analyzed. The precision of the method of estimating the cell numbers is indicated by a coefficient of variation of 5%. The experimental procedure is given for a short-term toxicological in vitro test in which the semiautomatic counting procedures can be performed within 1.5 h.

A semiautomatic image analyzer for cell counts in monolayers. III. Statistical considerations

The image-analyzing system described in the companion paper (Thorén and Lanke, 1989) is considered from a statistical point of view. Special attention is given to the following applications: simple cell counts, viability estimation, and toxicity estimation. Different estimators are considered, their variances are discussed, and it is shown how to compute standard errors in different situations.

Mode of inheritance as indicated by one-sided and two-sided familial taint: with an application to schizophrenia

Among his various approaches to an understanding of schizophrenic inheritance, whether dominant or recessive, Rüdin (1916) also compared the respective frequencies of one-sided and two-sided familial taint. Essen-Möller (1949) tried the idea on another sample, but neither of us arrived at a definite choice. Later on Slater (1966) surprisingly demonstrated that unilaterality is typical not only of dominant but also of polygenic transmission. In the present paper we adjust Slater's computation and, in so doing, accentuate his result. We also find a similar preponderance of unilaterality on a recessive model, and offer an explanation for this. The findings substantially reduce the efficacy of laterality of taint as an indicator of mode inheritance.

Incidence of anxiety in the Lundby Study: changes over time during a quarter of a century

2,550 persons from a geographically delimited area in Sweden were examined and described by a team of 4 psychiatrists in 1947. Mental disorders, personality traits, social factors etc. were recorded for all but 1% of the population. Irrespective of domicile the same persons were examined in the same way first 10, then another 15 years later. The incidence of 'Anxiety' up to 60 years of age was 9.9% in men and 19.7% in women. The majority of both sexes had their first episode as young adults or in the younger middle age (30-39 years). Among men with a 'severe and medium' impairment, the cumulative probability of disease was higher in the 15-year period 1957-1972 than in the 10-year period 1947-1957.

Predictors of alcoholism in the Lundby Study. II. Personality traits as risk factors for alcoholism

In 1957 all inhabitants (2,612) in a delimited geographical area, Lundby, were examined by a psychiatrist. Personality traits were scored for each individual. During the following 15 years 58 men became alcoholics (44 who had been 15 years or over in 1957). Among the men who in 1957 were scored 'subsolid in combination with symptom neurosis' the risk of becoming an alcoholic was increased 13.5 to 15.8 times. Protective against alcoholism was 'subvalidity in combination with psychosomatic symptoms'. The men with this combination had their risk decreased 12 times. The prediction of alcoholism depended on which factors and which combinations were used. With a sensitivity of 50% a specificity of almost 90% was reached; with a sensitivity of 60% specificities between 70% and 80% were reached.

Predictors of alcoholism in the Lundby Study. I. Material and methods

In this prospective longitudinal study over 15 years (1957 to 1972) the background factors for those who became alcoholics and those who did not were registered before anybody knew what the outcome would be. The population (2,612 inhabitants) lived in 1957 in a delimited area in the South of Sweden, Lundby. In 1957 nearby everyone (98%) was examined by a single psychiatrist, and again in 1972, irrespective of domicile, by two psychiatrists. Among the men who at the outset did not misuse alcohol, 58 became alcoholics. These alcoholics were compared with the non-alcoholics regarding e.g. personality traits, social factors and interactions between factors.

U-shaped association between mortality and blood pressure in a thirteen-year prospective study

The present study was performed to investigate the predictive value of casual blood pressure recordings for mortality in a geographically defined population (n = 1917), for which the primary health care services are responsible. Isotonic regression of blood pressure on age was used to define groups with low, medium and high blood pressure. In the age group 40 to 69 years mortality turned out to be a U-shaped function of blood pressure. In those aged 70 years and over blood pressure appeared to be of less importance as a risk indicator of death. The study has shown that a limited number of subjects in a defined population can be utilized in epidemiological studies of mortality as a function of blood pressure if an appropriate statistical method is used in the analyses, thereby justifying our model for studies in primary health care.

Predictors of alcoholism in the Lundby Study. III. Social risk factors for alcoholism

In 1957 all inhabitants (2,612) in a delimited geographical area, Lundby, were examined by a psychiatrist, and social factors were evaluated for each individual. During the following 15 years 58 men became alcoholics. Among the men who in 1957 were in the age group 0-14 years and belonged to a 'gang', the risk of becoming an alcoholic was 100-fold increased. 'Gang' was also an important factor in the age group 15-24 years. 'Crisis' was an important factor among those over 14, and 'disintegrated environment' in the age group 25-59 years. In the latter age group occupations such as 'entrepreneur', became important as a precipitating factor. 'Married' was the only protective factor found.

Prevalence and incidence of senile and multi-infarct dementia in the Lundby Study: a comparison between the time periods 1947-1957 and 1957-1972

In a recent Lundby paper, based on the original 1947 Lundby cohort [Hagnell et al., 1983], we reported a diminishing trend in the incidence of both senile and multi-infarct dementia from the first period of study 1947-1957 to the second, 1957-1972. In the present study we use the total Lundby population, including those who entered the Lundby project in 1957, as a basis for our calculations. The findings indicate no statistically significant changes in the prevalence and incidence of senile and multi-infarct dementia during the observation period 1947-1972.

Mortality and age psychosis in the Lundby Study: death risk of senile and multi-infarct dementia. Changes over time in a prospective study of a total population followed over 25 or 15 years

Persons suffering from age psychosis are known to have a high mortality rate. During the last decades there has been a general improvement in the standard of living and the availability of medical resources for the elderly in most western countries. It has been suggested that persons with a diagnosis of age psychosis have benefited from these changes and live longer with their illness than they did before. The Lundby cohort comprises 3,563 persons from a total population followed concerning mental disorders (psychiatrically treated as well as untreated) for 15 or 25 years. In the present Lundby Study we have calculated the changes over time concerning death risk among persons with senile and multi-infarct dementia and overmortality associated with these two main subgroups of age psychosis. We found that the prognosis in terms of mortality had not undergone any statistically significant change during the 25-year period 1947-1972 among persons in the Lundby cohort with a diagnosis of senile and multi-infarct dementia.

Prevalence of age psychosis and mortality among age psychotics in the Lundby Study. Changes over time during a 25-year observation period

It has been suggested that persons suffering from age psychosis have benefited from social and medical improvement in the society so that they live longer with their illness than they did before. The Lundby cohort comprises 3,563 persons from a total population, followed concerning mental disorders for 15 or 25 years. In the present study we have investigated the changes over time concerning prevalence of age psychosis and mortality among age psychotics in the Lundby Study during the 25-year observation period. When the first 10-year period was compared with the second 15-year period, the figures for average prevalence of age psychosis and death risk associated with a diagnosis of age psychosis had generally decreased in both sexes, but the differences found between the two time periods did not reach statistical significance. A significantly lower mortality during the second time period was found among mentally healthy women.

The overall mortality rate in patients with total hip arthroplasty, with special reference to coxarthrosis

The mortality rate was calculated in 1385 patients with total hip arthroplasties compared with the population at risk in the period from 1968 to 1981. In elderly women with coxarthrosis, after the age of 70, the mortality rate decreased after the first postoperative year. There was no such effect in men. In women, there were no changes in mortality rate in those who had had revision operations, whereas in men operated on for coxarthrosis who were over the age of 70, there was an increased mortality rate after the first postoperative year following revision. Patients operated on for complications after hip fracture and/or rheumatoid arthritis had an increased mortality rate after the first postoperative year, including both women and men below age 70.

Current trends in the incidence of senile and multi-infarct dementia. A prospective study of a total population followed over 25 years; the Lundby Study

Organic brain syndromes among the elderly have been studied prospectively in a total population during the 25-year period 1947-1972. The population (2,550 persons) originates from a geographically delimited area in southern Sweden (Lundby). The original population has been followed for 25 years irrespective of domicile. A comparison of incidences for the first 10-year period (1947-1957) and the second 15-year period (1957-1972) shows a decrease in organic brain syndromes in the population concerning multi-infarct as well as senile dementias.

Mortality and hidden mental disorder in the Lundby Study. Age-standardized death rates among mentally ill 'non-patients' in a total population observed during a 25-year period

In the Lundby Study, all mental illnesses, treated as well as untreated, that occurred during a 25-year period in a geographically defined Swedish general population sample were evaluated. All forms of psychiatric services used by the population during the same period were registered. The present study investigates the mortality pattern of mentally ill persons who did not receive psychiatric specialist treatment. Men with a 'hidden' mental disorder showed a significantly increased mortality from non-violet causes (p less than 0.001). The relative somatic death risk in this group was even slightly higher than that found among mentally ill men who had received psychiatric specialist care. The somatic overmortality found among women with a hidden mental disorder did not reach statistical significance, while mentally ill women who had been treated showed a significant excess mortality from natural causes (p less than 0.05). The total number of violet deaths was small and calculations on violet death risks were performed only for men. Among men with a hidden mental disorder the age-standardized violent death risk was twice that of the total male population, but the increase did not reach statistical significance. Men with a treated mental disorder showed a significant over-mortality from violent causes (p less than 0.001).